D. Fritts - Academia.edu (original) (raw)
Papers by D. Fritts
Geophysical Research Letters, 2010
The Weber sodium lidar at the Artic Lidar Observatory for Middle Atmosphere Research (ALOMAR) nea... more The Weber sodium lidar at the Artic Lidar Observatory for Middle Atmosphere Research (ALOMAR) near the Andoya Rocket Range in Norway (69N, 16E) has made measurements of the temperature and radial wind profiles near the mesopause for 750 hours over 105 days between 2000 and 2006. These measurements were made during both night and day with data campaigns occurring in all months of the year. The altitude range was approximately 80 to 105 km in winter and 85 to 97 km in summer. We will present the seasonal variation of the daily mean temperature profiles and compare to previous falling sphere and lidar measurements at the same site. We will also show a preliminary calculation of temperature amplitudes, phases, and variability of the semidiurnal and diurnal tides.
Annales Geophysicae, 2009
We provide here an overview of, and a summary of results arising from, an extensive experimental ... more We provide here an overview of, and a summary of results arising from, an extensive experimental campaign (the Spread F Experiment, or SpreadFEx) performed from September to November 2005, with primary measurements in Brazil. The motivation was to define the potential role of neutral atmosphere dynamics, specifically gravity wave motions propagating upward from the lower atmosphere, in seeding Rayleigh-Taylor instability (RTI) and plasma bubbles extending to higher altitudes. Campaign measurements focused on the Brazilian sector and included ground-based optical, radar, digisonde, and GPS measurements at a number of fixed and temporary sites. Related data on convection and plasma bubble structures were also collected by GOES 12, and the GUVI instrument aboard the TIMED satellite.
AIAA/AAS Astrodynamics Specialist Conference and Exhibit, 2006
2003 User Group Conference. Proceedings, 2003
We employ high-resolution DNS methods to examine the dynamics, energetics, and structure of subma... more We employ high-resolution DNS methods to examine the dynamics, energetics, and structure of submarine wakes evolving to late times. Because of the computational focus of the project, our efforts are twofold: both computational efficiency and numerical accuracy. Thus our codes are highly optimized on the DoD computational platforms, scale linearly with increasing CPUs, and employ methods to achieve high computational
Journal of Geophysical Research: Atmospheres, 2013
Journal of Geophysical Research, 1997
The relationship between quasi 2-day (QTD) oscillations in the neutral wind near 90 km altitude, ... more The relationship between quasi 2-day (QTD) oscillations in the neutral wind near 90 km altitude, and in the critical plasma frequency (f oF2) of the ionospheric F region, is investigated for the June-September 1992 period. Wind data are analyzed from MF radar stations at Christmas Island (1.9øN, 202.7øE), Hawaii (20.8øN, 203.5øE), and Saskatoon (52.1øN, 253.4øE) with emphasis on characterizing temporal
Annales Geophysicae, 2002
In an earlier paper tidal data (1990)(1991)(1992)(1993)(1994)(1995)(1996)(1997) from six Medium F... more In an earlier paper tidal data (1990)(1991)(1992)(1993)(1994)(1995)(1996)(1997) from six Medium Frequency Radars (MFR) were compared with the Global Scale Wave Model (GSWM, original 1995 version). The radars are located between the equator and high northern latitudes: Christmas Island (2 • N), Hawaii (22 • N), Urbana (40 • N), London (43 • N), Saskatoon (52 • N) and Tromsø (70 • N). Common harmonic analysis was applied, to ensure consistency of amplitudes and phases in the 75-95 km height range. For the diurnal tide, seasonal agreements between observations and model were excellent while for the semi-diurnal tide the seasonal transitions between clear solstitial states were less well captured by the model.
Annales Geophysicae, 2009
We provide here an overview of, and a summary of results arising from, an extensive experimental ... more We provide here an overview of, and a summary of results arising from, an extensive experimental campaign (the Spread F Experiment, or SpreadFEx) performed from September to November 2005, with primary measurements in Brazil. The motivation was to define the potential role of neutral atmosphere dynamics, specifically gravity wave motions propagating upward from the lower atmosphere, in seeding Rayleigh-Taylor instability (RTI) and plasma bubbles extending to higher altitudes. Campaign measurements focused on the Brazilian sector and included ground-based optical, radar, digisonde, and GPS measurements at a number of fixed and temporary sites. Related data on convection and plasma bubble structures were also collected by GOES 12, and the GUVI instrument aboard the TIMED satellite.
Advances in Space Research, 2004
The mesosphere/lower thermosphere (MLT) wind data from the 46 ground-based (GB) MF and meteor rad... more The mesosphere/lower thermosphere (MLT) wind data from the 46 ground-based (GB) MF and meteor radar (MR) stations, located at the different latitudes over the globe, and the space-based (SB) HRDI data were used for constructing of the empirical global climatic 2-D prevailing wind model at 80-100 km heights for all months of the year. The main data set is obtained during 1990-2001 period. It is shown that the three datasets (MF, MR, HRDI) are mainly well correlated. However, a certain systematic bias between the GB and SB data at 96 km exists, as well as that between the MF and MR data higher 88 km. Simple correction factors are proposed to minimize these biases. The 2-D distant-weighted least-square interpolation procedure for some arbitrary collection of points was used for drawing model contour plots. The model is available in the computer readable form and may be used for construction of the new CIRA model.
Field and numerical studies of the evolution of the atmosphere in the near-ideal, basinshaped cra... more Field and numerical studies of the evolution of the atmosphere in the near-ideal, basinshaped crater have led to an extensive dataset exhibiting many stable boundary layer phenomena and their interactions with background flows.
Geophysical Research Letters, 2010
The Weber sodium lidar at the Artic Lidar Observatory for Middle Atmosphere Research (ALOMAR) nea... more The Weber sodium lidar at the Artic Lidar Observatory for Middle Atmosphere Research (ALOMAR) near the Andoya Rocket Range in Norway (69N, 16E) has made measurements of the temperature and radial wind profiles near the mesopause for 750 hours over 105 days between 2000 and 2006. These measurements were made during both night and day with data campaigns occurring in all months of the year. The altitude range was approximately 80 to 105 km in winter and 85 to 97 km in summer. We will present the seasonal variation of the daily mean temperature profiles and compare to previous falling sphere and lidar measurements at the same site. We will also show a preliminary calculation of temperature amplitudes, phases, and variability of the semidiurnal and diurnal tides.
Annales Geophysicae, 2009
We provide here an overview of, and a summary of results arising from, an extensive experimental ... more We provide here an overview of, and a summary of results arising from, an extensive experimental campaign (the Spread F Experiment, or SpreadFEx) performed from September to November 2005, with primary measurements in Brazil. The motivation was to define the potential role of neutral atmosphere dynamics, specifically gravity wave motions propagating upward from the lower atmosphere, in seeding Rayleigh-Taylor instability (RTI) and plasma bubbles extending to higher altitudes. Campaign measurements focused on the Brazilian sector and included ground-based optical, radar, digisonde, and GPS measurements at a number of fixed and temporary sites. Related data on convection and plasma bubble structures were also collected by GOES 12, and the GUVI instrument aboard the TIMED satellite.
AIAA/AAS Astrodynamics Specialist Conference and Exhibit, 2006
2003 User Group Conference. Proceedings, 2003
We employ high-resolution DNS methods to examine the dynamics, energetics, and structure of subma... more We employ high-resolution DNS methods to examine the dynamics, energetics, and structure of submarine wakes evolving to late times. Because of the computational focus of the project, our efforts are twofold: both computational efficiency and numerical accuracy. Thus our codes are highly optimized on the DoD computational platforms, scale linearly with increasing CPUs, and employ methods to achieve high computational
Journal of Geophysical Research: Atmospheres, 2013
Journal of Geophysical Research, 1997
The relationship between quasi 2-day (QTD) oscillations in the neutral wind near 90 km altitude, ... more The relationship between quasi 2-day (QTD) oscillations in the neutral wind near 90 km altitude, and in the critical plasma frequency (f oF2) of the ionospheric F region, is investigated for the June-September 1992 period. Wind data are analyzed from MF radar stations at Christmas Island (1.9øN, 202.7øE), Hawaii (20.8øN, 203.5øE), and Saskatoon (52.1øN, 253.4øE) with emphasis on characterizing temporal
Annales Geophysicae, 2002
In an earlier paper tidal data (1990)(1991)(1992)(1993)(1994)(1995)(1996)(1997) from six Medium F... more In an earlier paper tidal data (1990)(1991)(1992)(1993)(1994)(1995)(1996)(1997) from six Medium Frequency Radars (MFR) were compared with the Global Scale Wave Model (GSWM, original 1995 version). The radars are located between the equator and high northern latitudes: Christmas Island (2 • N), Hawaii (22 • N), Urbana (40 • N), London (43 • N), Saskatoon (52 • N) and Tromsø (70 • N). Common harmonic analysis was applied, to ensure consistency of amplitudes and phases in the 75-95 km height range. For the diurnal tide, seasonal agreements between observations and model were excellent while for the semi-diurnal tide the seasonal transitions between clear solstitial states were less well captured by the model.
Annales Geophysicae, 2009
We provide here an overview of, and a summary of results arising from, an extensive experimental ... more We provide here an overview of, and a summary of results arising from, an extensive experimental campaign (the Spread F Experiment, or SpreadFEx) performed from September to November 2005, with primary measurements in Brazil. The motivation was to define the potential role of neutral atmosphere dynamics, specifically gravity wave motions propagating upward from the lower atmosphere, in seeding Rayleigh-Taylor instability (RTI) and plasma bubbles extending to higher altitudes. Campaign measurements focused on the Brazilian sector and included ground-based optical, radar, digisonde, and GPS measurements at a number of fixed and temporary sites. Related data on convection and plasma bubble structures were also collected by GOES 12, and the GUVI instrument aboard the TIMED satellite.
Advances in Space Research, 2004
The mesosphere/lower thermosphere (MLT) wind data from the 46 ground-based (GB) MF and meteor rad... more The mesosphere/lower thermosphere (MLT) wind data from the 46 ground-based (GB) MF and meteor radar (MR) stations, located at the different latitudes over the globe, and the space-based (SB) HRDI data were used for constructing of the empirical global climatic 2-D prevailing wind model at 80-100 km heights for all months of the year. The main data set is obtained during 1990-2001 period. It is shown that the three datasets (MF, MR, HRDI) are mainly well correlated. However, a certain systematic bias between the GB and SB data at 96 km exists, as well as that between the MF and MR data higher 88 km. Simple correction factors are proposed to minimize these biases. The 2-D distant-weighted least-square interpolation procedure for some arbitrary collection of points was used for drawing model contour plots. The model is available in the computer readable form and may be used for construction of the new CIRA model.
Field and numerical studies of the evolution of the atmosphere in the near-ideal, basinshaped cra... more Field and numerical studies of the evolution of the atmosphere in the near-ideal, basinshaped crater have led to an extensive dataset exhibiting many stable boundary layer phenomena and their interactions with background flows.